Fluid transmissions utilize a fluid or oil which should be filtered during use of the transmission. Unfortunately, the filtering of the transmission fluid for many transmissions is very inadequate.
For example, fluid transmissions typically include upper and lower housing sections held together by threaded fasteners, with the lower housing section confronting the pan. The lower housing section has a wall which defines an open-ended cavity which opens into the pan. In at least one prior art construction, a screen extends across the open-ended cavity to provide some mechanical filtering of the trasmission fluid as it passes through the screen. This screen is incapable of filtering the fluid to the extent required for maximum life of the fluid and the transmission.
In an attempt to provide improved filtering for transmission fluid, a filter has been provided which has a much greater filtering area than the screen and an ability to filter out much smaller particles. This filter includes two layers of porous material separated by an apertured interior support to provide a two-sided hollow filter. This filter does a much better job of filtering transmission fluid, but unfortunately due to its construction, it cannot be used with many automotive and truck fluid transmissions.